Bisphosphonate-associated osteonecrosis (BRONJ) is an adverse event associated with bisphosphonate drug treatment. An 81-year-old female has been taking bisphosphonates orally once a month for three years complained of pain in the left mandibular molar area after implant placement. Tenderness and fistula were formed. Extensive osteosclerosis in posterior area of the left mandible and bone resorption around distal side of #37i were shown on radiographs. She was given oral antibiotics for 6 weeks and bone resorption was improved. A 70-year-old male had a history of intravenous injection of bisphosphonates for blood cancer complained of #46i implant mobility. There was buccal fistula on #45 site. Radiographically, severe bone resorption and extensive osteosclerosis were shown. He was treated with removal of implant and inflammatory tissue. Patients who have taken bisphosphonates may develop BRONJ after tooth extraction or implant placement and are needed to meticulous plaque control for preventing BRONJ.

Abstract
Ⅰ. INTRODUCTION
Ⅱ. CASE REPORT
    1. Case 1
    2. Case 2
ACKNOWLEDGEMENT
REFERENCES

• 홍준의(전남대학교 치의학전문대학원) | Joon-Eui Hong (School of Dentistry, Chonnam National University, Gwangju, Republic of Korea)
• 양지연(전남대학교 치의학전문대학원 치주과학교실, 치의학연구소) | Ji-Yeon Yang (Department of Periodontology, School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju, Republic of Korea 3)Department of Dentistry, Chonnam National University Hospital,)
• 정하나(전남대학교병원, 화순병원, 치과) | Ha-Na Jeong (Department of Dentistry, Chonnam National University Hospital, Hwasun, Republic of Korea)
• 김옥수(전남대학교 치의학전문대학원 치주과학교실, 치의학연구소, 전남대학교 치의학전문대학원 경조직바이오인터페이스연구센터) | Ok-Su Kim (Department of Periodontology, School of Dentistry, Dental Science Research Institute, Chonnam National University,Hard-Tissue Biointerface Research Center, School of Dentistry, Chonnam National University,) Corresponding author